Adjustable spindle bearing for hobbing machines



I 1,676,310 W. F. ZIMMERMANN I .ADJUSTABLE SPINDLEv BEARING FOR HOBBING MACHINES July 10; T928.

Fi led March 13, 1925 3 Sheets-sheaf.

Ewuenboz amimw ildly 10, 1928.

W. F. ZIMMERMANN ADJUSTABLE SPINDLE BEARING FOR HOBBING MACHINES 44 mm Q? III/II IIII/I/IIIIIII JfilflO, 192s. 1,626,310

- W. F. Z IMMERMANN ADJUSTABLE SPINDLE BEARING FOR HOBBjING MACHINES s Shets-Sheet 5 5 Filed March 15, 1925 I r v Patented July 10, 1928.

barren STATE-s WILLIAM r. znvnunniaenit or arnnwoon, new innsny, nssrenon To OULD Y EBERHARDT, or NEWARK, NEW JERSEY, A oonronA'rI'oN or new JERSEY.

ADJUSTABLE srrnnnn BEARING FOR none-Inc. iancnmns Application filed March 13, 1925. Serial No. 15,218.

. This invention is devoted to precision marotation of the cutter about its own axis, a.

rotation of the blank about its own axis, and

a translation between the cutter and the blank. The coordination is very involved and must be exactly maintained because any irregularity in any one of the component mo-. tions will disproportionately influence the others and the ultimate relativity will be unduly distorted and anunprecise product will be. generated.

Any side-play of the cutter in the direction of its axis will introduce a'disarrangement into the rotation of thework relative to the cutter; any dislocation of the axis of the cutter toward or away from the axis of the blank, or any converse dislocation of the axis of the work, will cause a departure from the true depth of tooth; any deviation from' a straight-line translation in the feed or bodily travel of the cutter will create a com plex error in the generation curves, etc. r Nor does it suflice to depend upon an initially correct setting of a structurally accurate machine by reason of the fact that the metals employed have different co'efiicients ofexpansion and because temperature variations, are created, during the period of operation, by the friction of bearings and the working of the cutter. It follows that a bearing, which is not too loose at the beginning, would become too tight after the parts have warmed up to the conditions of normal running. To meet this contingency and enable the intrinsic accuracy of the machine to be uniformly maintained, the mechanism should be constructed to afford its user full convenience and facility in effecting compensation during the working period; it being especially essential that such adjust ments may be made in an evenly progressive manner and without any rangement of the mounting.

Not only is it important that the machine should embody compensative means, aforesaid, but it is also consequential that its mechanical arrangement should be such as to reduce to a minimum the occasions for maof the tooth preliminary de- I nipulating such means." For example, its

structure should be such that expansions (which are unavoidably caused by the heat) will be accommodated in a manner leastable to influence unfayorahly the correct rela-. tivlty of the working elements.-

-How these objectives may 'beattained, will now be explained in the followingspecification of a concrete example of the invention; reference beinghad to the drawings of Wh =h1; r e

In the accompanying drawings, 1 is an assembly view of the work spindle and the cutter. spindle with the inter-connecting gearing. F 2 is a sectional elevational view of the work spindle. F 3 is aps'ection along the line 3+3 of Fig. 2. Fig. 4 is an. elevational. view of the cutter carriage and the cutter-spindle mounted thereon. Fig. .5.

is asection along the line 5- 5 of Fig; i. Fig. 6 is an end elevational view of the. cutter carriage and Fig.7 is a section alongthe line 7 57 of. Fig. 4. 3

Referring to the accompanying drawings and particularly to the assembly view shown in; Fig. 1-, a cutter spindle 1, which carries a suitable cutter or hob 2,v is rotated and given amo-v,ement' of translation with re-' spect to the work which is carried by a work spindle '.-The work spindle 3 and the cutter spindle lrmust be rotated at a 'pred'etermined ratio with respect to each other and moreover the h b'Q-and thework must be positioned in exact relation with respect to each-other. The eutter'spindle'l is operated by nieanslof a worm gear wheel 4 which meshes with a wor'in5; The worm 5 has a sp'lined 'connection'with a shaft 6 'in-order topermit vertical movement of the cutter spindle I, the worm wheel 4 and the worm 5, in accordancewith the rotation of the cutter spindle; The. spline shaft 6 carries. a bevel gear -wheel' 7 which-1neshes with a' bevel gear wheel .8 ona shaft- 9. The shaft 9 carries abe'vel gearwheel 10 which meshes with a bevelgear 111011. a shaft 12.- The shaft 12 is connected spur gear wheels -which meshes, with a gear wheel 17 on. the

shaft 18. The shaft 18 carries a worm'member 19 which operates a. worm wheel 20 on the work spindle 3. By means of such gearing, as above set forth, the cutter spindle 1 and the work spindle 3 are rotated in correctrelation with respect to each other.

It is not only necessary to effect the movement of translation and rotation of the cutter spindle 1 in exact relation with respect to the rotation of the work spindle 3 but it is also necessary to support the two spindles l and 3 in bearingsso to prevent any movement therein other than what has been determined. The cutter spindle 1 is supported in bearings 21 and 22 which must insure against any casual movement by the spindle during the cuttingoperation. Moreover, the bearings mustbe adjustable as to the diameter of the spindle and accurately fit the spindle under cutting conditions. It should be noted that during the operation of the hobbing machine, the spindle 1 tends to become hot inasmuch as the bearings 21 and 22 must be snugly fitted thereto. The heating of the spindle causes it to enlarge as well as to expand axially and interfere with the axial adjustment of the spindle with respect to one of the bearings. Provision is made in a hobbing machine constructed in accordance with my invention to insure against inaccurate work when the spindle is elongated by heat. A full description of the adjustment for the bearings 21 and 22 will be given when reference is made to Figs. 4, 5, 6 and 7 of the drawings.

Referring to Figs. 2 and 3 of the drawings, the work spindle 3 is shown supported by a bearing frame 23 which in turn is suitably connected to a frame 24. A work spindle bushing 25, which is preferably composed of bronze, is mounted within the bearing frame 23 and directly supports the work spindle 3. The bushing 25 has a cylindrical outside surface which is fitted to the bearing frame 23 and is provided with a conical vent any rotation of the bushing in accordance with the movement of the spindle and a recess 29 is formed in the bearing frame 23. below the plate 27 for carrying an adjusting nut 30. The adjusting nut 30 is provided with threads which engage threads 31 on the bushing 25. Suitable worm teeth 32, which mesh with a worm 33, are formed on the outside of the nut. The worm 33 is formed on a shaft 34 which is supported in the bearing frame 23, as shown in Fig. 3 of the drawings. The end 35 of the shaft 34 is preferably shaped to receives a wrench to facilitate manual adjustment thereof and thereby effect a longitudinal adjustment of the bushing 25 within the bearing frame 23. In the above construction itis apparent rotation of the worm 33 and the nut 30 effect longitudinal movement of the bushing 25. irrespective of the operating condition of the work spindle 3. Thus, the adjustment of the bushing can be effected when the spindle 3 is in rotation.

A supporting plate 37, which is secured to the frame 24 by bolts 38, is provided for centralizing the bearing frame 23 at the lower end thereof. The worm wheel 20, which operates the work spindle, is mounted on the spindle 3 adjacent to the bearing frame 23, as shown in Fig. 2 of the drawings. A nut 39 is secured to the spindle 3 adjacent to the worm wheel 24 for controlling the end fit of the spindle within the bearing. In this regard it will be noted the nut 39 holdsthe head 26 of the spindle against the plate 27 and holds the worm wheel 20 against the end of the bearing frame 23. It should also be noted that the restriction of the spindle axially in the bearing is eflected by an adjust able means which is separate and distinct from the means which adjusts the bearing with respect to the diameter of the spindle. Moreover, as above set forth, the adjustment of the bearing with respect to the diameter of the spindle may be effected while the spindle is rotating. 5

In many bobbing machines heretofore constructed the adjustment of the spindle as to end play andalso the adjustment of the bearing with respect to the diameter of the spindle have been effected solely by means of a nut similar to the nut 39 which is secured to the end of the spindle. When two adjustments are effected by such nut, it is impossible to effect any adjustment of the bearing as to the diameter of the spindle when the spindle is rotating. Moreover, it is necessary to remove some of the metal beneath the head of the spindle whenever it is desired to adjust the position of the spindle bushing.

Referring to Figs. 4, 5, 6 and 7 of the drawings, the cutter spindle bearings 21 and 22 are shown supported on a carriage 40. The carriage 40 operates on suitable guideways 41 and 42 which are a part of the upright stanchion 43. The carriage 40 is held in position on the guide ways by means of straps 44, as best shown in Fig. 5 of the drawings and suitable gibs 45 are associated with the straps 44. A vertical screw shaft 46 is provided for effecting vertical movement of the carriage 40 in timedrelation to the rotation of the cutter spindle 1 and also in timed relation to the rotation of the work spindle 3. Inasmuch as my invention is not particularly related tothe details of the power means for effecting vertical movement ill) of the carriage, it is deemed unnecessary to further describe it.

A plate A7, which is secured to the-carriage by means of bolts iO is provided with a wsenn-circular recess within which the bearings 21-and 22 are mounted; Provision is made, as will be hereinafter set forth, for effecting movement of the bearing 21'along.

theqplate t? for positioning the cutter spin dle with respect to the work. V

The bearing 21 comprises a bearingframe 49 which isdirectly secured to the-plated? by means of straps 50 and bolts 51. A bushing 52, which is preferably coinposedof bronze,; is provided in the bearing frame 49 for directly engaging the cutter spindle 1. The bronze bushing 52 has a cylindrical fit with the bearing frame 49 and a conical lit with the tapered section of the cutter spindle 1. The bronze bushing 52 is adjusted longitudinally to snugly fit the cutter spindle by means of a nut 53 which is constructed very similar to the nut 30 for adjusting the position of the bronze bushing surrounding the work spindle. The nut 53 is connected to the bushing 52 by means of screw threads 54- and is provided withigear teeth 55 for meshbolt 62.

ing with a. pinion 56 on ashort shaft 57. The shaft 57 is manually operated by means of a wrench applied to head 58. as shown in Fig. 5' of the drawings. Thus, by operating the s'haft'57, the nut 53 is rotated for varying the longitudinal position of the bushing 52 within the bearing fraineeit). The bushfling 52 is prevented from rotating with the cutter spindle 1 by means of suitable member 59 which is splined thereto. The nut 53- is rotatably mounted in a recess 60 formed in the bearing frame 49 and is held in position by means of a retaining plate 61 which in turn is secured in position by m'cansof a A hardened steel plate63 is secured to the one end of the bearing frame 49 by means of a screw 64 and a dust collar 65, as shown in Fig. 5 of the drawings, is held in position by the samescrew 64.- 'The dust collar 65 prevents any dust from entering the hearing so as to interfere with the bearing sur-' faces which prevent longitudinal movement of the cutter spindle with respect to the bearing. Although the dust collar 65 and the plate 63 are shown as separatemembers 68 from rotating in order to insure against;

any relative rotation surfacebetween it and the adjusting nut 70. The-fadju-sting nut 70 is threadably connected to the cutter spindle 1 and serves to preventl'ongitudinal move ment of the spindle with respect to the bear-l ing 21. In this regard it willbe noted the head 67 of the spindle is disposed on one side of the steel plate 63 and the nut 70 is disposed upon the opposite side of said hard ened steel plate. The hardenedsteel plate" 63, as above set forth, secured to the bearing frame 49 by means of the screw 64; The adjusting nut 70 is located at the-end of the bearing 21which is adjacent to the hob or cutter 71. The adjusting nut is so positioned in order to prevent the elonga tion'of the spindle by reason of heat from changing the end-fit thereof. The bearings for the cutter spindle must be adjusted very snugly and, by reason thereof, and because" of the heat flowing from the cutter, the te'in perature of the cutter spindle will rise, du-r ing the operation of the machine. The f portion of the cutter spindle included be tween the nut 70 and the hob 71.'is very short. Accordingly, the effect on the work when the spindle is elongated or byheat is negligible,

expanded A plate 72 is provided for covering the opening in the main spindle bearing 21 and issecured in position by set'screws 73. 1 The plate 72 can be easily removed Whenever it is desired to adjust the nut 70 for changing the position of the bushing 52 in the hearing I frame 49. I j 1 The hob or cutter 71 iskeyed on the cut terspindlel adjacent to a collar 7e and is held in position by means of nut 7 5. The

dle 1, is preferably composed of, bronze and for such reason may better be indi= rectly connected to the spindle. 'As shown in Fig. 50f the drawings, the worniwhee'l 4 is secured to a steel plate 78.' The steel plate? 8 is provided with a hub portion '79 i which is splinedto the spindle 1 and whichprojects through a bearing 80. Anut 81, which is thread'ably connected tothe end of the hub portion 79,- engages a balance wheel 82'for holding the steel plate 78 and the parts connected thereto against longitudinal movement with respect to the bearing 80 The cutter spindle 1, as above set forth, has

a splined connectionwith th portion 79 v [and the balance wheel 82 is keyed to h hub portion. Y 1 l i -The bearing 22st the op osite end of the .worin wheel 4:, which rotates the cutterspin cutter spindle 1 comprises a bearing frame 84 having a bronze bushing'85 niounted therein. The bronze bushing 85 has acoriical fit withthe bearing frame EAandhaS a cylindrical fit (to maintain coneentjricity and yet permit axial shifting) with a hardened steel sleeve 86 on the spindle 1; The hard"- ened steel sleeve 86 is preferably shrunk upon the spindle 1. The bronze bushing 85 is provided with alongitudinal slot therein in accordance with the usual practise to permit. such bushing to adjust itself to various longitudinal positions with respect to the bearing frame 8% and the hardened bushing 86. The longitudinal position of the bronze bushing 85 is controlled by means ofan adjusting nut 87 which similar in construction to the adjusting nuts heretofore described for varying the longitudinal positions of the busl'iingsin the various bearings. The nut 87 is threadably connected to the bronze bushing 85 and is positioned within a recess 88 formed in the bearing frame 84. A plate 89, which is secured to the frame 84 is provided for holding the nut 87 within the recess 88.

In Fig. 7 of the drawings is disclosed means for positioning thehob or cutter 71 with respect to the work. Such means comprises a short shaft 95 which is rotatably supported by the plate 47. Gear teeth 96 are formed on the lower end of the shaft for engaging the teeth of a rack 9'? on the bearing frame 49. The shaft has toothnotches formed in its upper end and these engage With a worm (indicated as a dotted square in Fig. 7) on the shaft turned by the hand-lever 98; this being for the purpose of manually effecting longitudinal movement of the cutter spindle l and the hob 71 carried thereby. The bearing 22 is secured to the plate 47 by means of straps 10-0 and bolts 101.

Without further analysis, the foregoing will so fully reveal the gist of this invention that others can, by applying currentknowledge, readily adapt it for various utilizations by retaining one or more of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of either the generic or specific asnects of this invention and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, I claim as new and desire to secure the following combinations and elements, or equivalents thereof, by Letters Patent of the United States:

1.- In a bobbing machine, the combination comprising a cutter spindle having a cutter mounted thereon; a bearing for said cutter spindle; a manual control for translating said bearing; a work spindle rotated in timed relation to the rotation of said cutter spindle; a bearing for supporting said work spindle; adjustable means for restricting the end play of the cutter spindle for preventing longitudinal movement thereof with respect to the bearing for the cutter spindle; means other than said adjustable means for varying the diametral fit of the bearing with the cutter spindle; and other means for varying the fit of the work spindle bearing with the work spindle. j

2. In a hobbing machine, the combina tion comprising a cutter spindle having a cutter mounted thereon; a bearing for sup porting the cutter spindle; adjustable means for controlling the diametral fit of the bearing with said spindle, said means being adjustable when the cutter spindle is in rotation; a work spindle rotated in timed rela tion to the rotation of the cutter spindle; a bearing for said work spindle; and variable means for controlling the diametral fit of the Work spindle bearing with the work spindle, said variable means being operative when the work spindle is in rotation.

3. In a hobbing machine, the combina-.

tion comprising a cutter spindle having a cutter mounted thereon; a Work spindle; means for rotating and relatively translating said spindles in timed relation to each other; a horizontal bearing for supporting said'cutter spindle; a vertical bearing for said work spindle; variable means for adjusting the cutter spindle bearing co -axially to fit the cutter spindle; means other than said variable means for preventing longitudinal movement of the cutter spindle with respect to the cutter spindle bearing; and two other means for adjusting the end fit of the work spindlev and the diametral fit of the work spindle bearing to the work spindle.

4. In a hobbing machine, the combination comprising a cutter spindle having a cutter mounted thereon; a work spindle; means for rotating and relatively translating said spindles in timed relation to each other; a horizontal' bearing for supporting said cutter spindle; a vertical bearing for said work spindle; means carried by the cutter spindle and connected to the cutter spindle bearing for adjusting the end fit of the cutter spindle; means carried by the cutter spindle bearing for adjusting the .diametral fit between the cutter spindle and its bearing; and two means for adjusting the end fit of the work spindle and the lit of the work spindle bearing to the work spindle.

5. In a hobbing machine, the combination comprising a cutter spindle having a cutter mounted thereon; a bearing for supporting the cutter spindle and having a movable member provided with aconical surface for engaging a conical surface on the spindle; means operable when the spindle is rotating to shift said member to establish a diametral fit with the cutter spindle; a work spin dle; a bearing for said work spindle and having a movable member provided with a conical surface for engaging a conical surface on the Work spindle; and means for shifting the member on the work spindle bearing when the work spindle is rotating. 6. In a hobbmg machlne, the combmatlon comprising a cutter spindle having acutter mounted thereon; a bearing for said cutter spindle; a work spindle rotated in timed relation to the'rotation of said cutter spindle; a bearing forv supporting said work spindle; adjustable means for limiting the end play of the cutter spindle and for preventing longitudinal movement thereof with respect to its bearing; means other than said adjustable means for varyingthe diametral fit of the bearing with the cutter spindle; variable means for limlting the end play at the work spindle for preventing longitu dinal movement thereof with respect to its bearing; and means independent of said variable means and operative irrespective of the operative condition of the'work spindle for varying the diametral fit of the work spindle bearing with respect to the work spindle.

7. In a hobbing machine, the combination comprising a cutter spindle having a cutter mounted thereon; a bearing for said cutter spindle; a work spindle rotated in timed relation to the rotation of said cutter spindle;

a bearing for supporting said workspindle;

adjustable means for limiting the end play of the cutter spindle for preventing longltudinal movement thereof with respect to its bearing; means other than said adjustable means :Eor varying the fit of thebearing with the cutter spindle; and means for vary-' ing the fit of the work-spindle bearingto the work spindle and for varying the end fit of the work, spindle Ebearing. i 8. In a ho'bbing machine, the combination comprising a cutter spindle having a cutter mounted thereon; a bearing for supporting the cutter spindle; a work-spindle rotated :in

'timed relation to the rotation of thecutter spindle; a bearing for supporting. the work spindle; means adjustable when the work spindle is rotating to fit. the work spindle bearing diametrically to the work spindle;

' adjustable means for preventing longitudinal movement of the work spindle with respindle; and means comprlsing a member spect to its bearing; ameans adjustable when the cutter spindle is rotating to fit the cutter spindle bearing diametrically to the cutter threaded to the cutterspindle and positioned by the cutter-spindle hearing at the end ad jacent. to the cutter for preventing longitudinal movement of the cutter spindle.

'9. In a hobbing machine, the eomblnation comprising a cutter spindle having a cutter mounted thereon; a bearing for supporting the-cutter spindle ;.a work spindle rotated in timed relation to the rotation of thecutter spindle; a bearing for supporting the work spindle; means comprlsing member thread= ed to the cutter spindle and positioned by the cntterspmdle ying at} @1133 end dd operable when the cutter is in rotation;

centto the cutter for preventing longitudh nal movement of the cutter spindle; and adjustable means for preventing longitudinal movement of the work spindle with respect to the bearing for the work spindle;

In ;a hobbing machine, the'combination comprising a cutter spindle havinga cutter mounted thereon; a bearing for supporting the cutter spindle; .a work'spindle rotated in timed relation to the rotation of the cutter spindle; a bearing for supporting the work spindle; means comprising a part rotatable as "a unit with thecutter spindle and coacting with the cutter-spindle bearing at a point adjacent: to the cutter for preventing longitudinal movement. of the cutter spindle;

"adjustable means for preventing longitudimeans comprising a member on the spindle for holding the spindle against longitudina-l movement with respect to the bearing to control the cutter spindle'end lit; a work spindle rotated in timed relation to. the rotation of-the cutter spindle; a. bearing for too said work spindle; and means comprising a member on the work spindle tor holding the work spindle against longitudinal movement with respect :to the work spindle bearmg. i v

12. In a bobbing -mach-ine, the combination 'comprising-acutter spindle having a cutter vmounted thereon; a bearing for supporting thecutter spindle; means for 'regu lating the diametrical fitof'the bearing with the cutter spindle; other means comprising a member shiftable on the spindle for holding'the spindle-against longitudinal niove- 'ment with respect'to the bearing; a work spindle rotated in stim'ed'relation to' the rotation ofthe cutter spindle;-a bearing for supporting the work spindle; meansfor con trolling thefit of the workspindile bearing "with the work spindle; and means comprising -a"member threaded to the workspindlefor holding the work spindle against longitudinal movement with respectto its bearing to control the work spindle lend fit.

13.21 machine-tool combininga cutter spindle having a cutter mounted? thereon 5 a bearing for said cutterv spindle; adjustable means entirely located closely adjacent @to said cutter for limiting the end play ofithe nutter spindle for preventing; leng'it dinal movementthereotwith respect t e its been 14. A machine-tool combining a cutter spindle having a cutter mounted thereon; a

'work' spindle rotated in timed relation to the rotation of said cutter spindle; a bear ing for said work spindle; means having an adjustable member located near one end of the work spindle for limiting the longitudinal movement thereof; and means located near the opposite end of the work spindle for adjusting the diametral fit of the bearing with the work spindle.

15. A machine-tool combining a cutter spindle; a work spindle rotated in timed relation to the rotation of the cutter spindle; a bearing for said work spindle; adjustable means for varying the fit of the bearing with the work spindle; and other means for limiting the longitudinal movement of the work spindle with respect to the bearing.

16. A machine-tool combining a cutter spindle having a cutter mounted thereon; a work spindle rotated in timed relation to the rotation of said. cutter spindle; a hearing for said work spindle; said bearing having a non-rotatable bushing provided with 'a conical surface for engaging the work spindle; meanscomprising an annular member threadably connected to said bushing for translating it to regulate the diametral fit of the bearing with the work spindle; and means comprising a second annular member threadably connected to the work spindle and secured tothe bearing for limiting the longitudinal movement of the work spindle with respect to its bearing.

17. A machine-tool combining a cutter spindle having a cutter mounted thereon; a work spindle rotated in timed relation to the rotation of said cutter spindle; a bearing for saidqwork spindle, said. bearing having'bushing provided with a conical surface for engaging the work spindle; means comprising an annular member threadably connected to said bushing and located near one end of the work spindle for varying the diamet-ral fit of the bearing with the work spindle; and other means comprising a second annular member threadably connected to the work spindle near the opposite end thereof and connected to the bearing for preventing longitudinal movement of the work spindle with respect to the bearing.

18. A machine-tool combining a cutter spindle having a cutter mounted thereon;

a bearing for said cutter spindle; adjustable means located adjacent to said cutter for regulating the extent of axial movement of the spindle; and means otherthan said ad-' justab-le means for adjusting the fit of said bearing to the spindle.

19. A machine-tool combining a cutter spindle having. a cutter mounted thereon;

said bearing.

a bearing for said spindle; adjustable means connected to the bearing adjacent to said cutter for preventing axial movement of the spindle; and means other than said adjustable means for adjusting the fit of said bearing to the spindle and comprising a member rotatably supported bysaid bearing.

20. A machine-tool combining a spindle; a bearing for supporting said spindle; adjustable means for regulating the size of the bore of the bearing and adjustable when the spindle is in rotation; and means, other than said bearing comprising a member threaded to the spindle for holding the spindle against longitudinal movement in 21. A machine-tool combining a spindle;-

a bearing frame, a bushing for supporting the spindle in said bearing frame said bushing having a cylindrical fit with said bearing frame and a conical fit with said spindle; means comprising a normally stationary member threadably connected to said bushing and rotatably restrained by said frame against any side shift for axially adjusting the bushing with respect to the spindle; and

means mounted on the bearing frame for turning said member.

22. A machine-tool combining a cutter spindle having a cutter mounted thereon; a bearing frame; a nonwotatable bushing for supporting the cutter spindle in said hearing frame, said bushing having a cylindrical fit with said bearing frame and a conical fit with said cutter spindle; an annular member rotatably supported in said bearing frame and threadably connected to said bushing for adjusting the bushing longitudinally with respect to the spindle.

23. A machine-tool combining a cutter spindle having a cutter mounted thereon; a bearing for supporting the cutter spindle; and a nut threadably connected to said spindle and supported in said bearing so as to permit rotation and to insure against movement of translation, said nut being connected tothe bearing adjacentv to the cutter to prevent substantial displacement of the cutter by reason of heating the cutter spindle.

24. A machine-tool combining a cutter spindle having a cutter mounted thereon; a bearing frame; a bushing for supporting the spindle in the frame, said bushing having a cylindrical fit with said bearing frame and a conical fit with said cutter spindle; and two annular members supported in said bearing frame for respectively controlling the end fit of the spindle and the fit between said bushing and the spindle, one of said annular members being threadably connected to the bushing and the other annular member being threadably connected to said spindle.

25. A machine-tool combining a cutter spindle having a cutter mounted thereon; a

sea

bearing for supporting said spindle; adjustable means for controlling the fit of the bearing With said spindle, said means being adjustable When the spindle is in rotation; andmeans other than said adjustable means for preventing longitudinal movement of the spindle with respect to the bearing to control the spindle end fit.

26. A machine-tool combining a cutter spindle having a cutter mounted thereon; a bearing frame; a bushing for supporting the cutter spindle in said bearing frame, said bushing having a cylindrical fit With said bearing frame and a conical fit with said cutter spindle; adjustable means for preventing longitudinal movement of the spindle in said bearing frame; and means for adjusting the longitudinal position of the bushing in said bearing frame, said means comprising a member rotatably located by the bearing frame and threadably connected to said bushing.

27. A machine-tool combining a cutter spindle having a cutter mounted thereon; a bearing frame; a bushing for supporting the cutter spindle in said bearing frame,

and means for adjusting the longitudinal position of the bushing in said bearing frame, said means comprising a member rotatably supported by the bearing frame and threadably connected to said bushing.

28. A machine-tool combining a cutter spindle having a cutter mounted thereon; a

bearing for centrally supporting the cutter spindle; a nut threadably connected to said spindle at the end of the bearing adjacent to said cutter; a shoulder formed on the spindle between said nut and the cutter; and a fixed plate located near said cutter and adapted to be clamped between the nut and said shoulder to prevent axial movement of the spindle. a

In Witness whereof, I have hereunto subscribed my name.

WILLIAM F. ZIMMERMANN. 

